Roadway or street lighting luminaires are, of course, well-known. One type, the horizontal burning type is, of course, equally well-known. In this type of luminaire, one end of the luminaire is mounted on a horizontal mast, the other end being cantilevered from the mast mounting. The luminaire is essentially comprised of two joined housings, an upper housing and a lower housing. The mounting of the luminaire to the mast is generally performed in the upper housing. The lower housing is generally hinged to the upper housing at the mounting end thereof. The remote or other end of the lower housing is latched to the upper housing by a manually operable latch. Such latches with but minor variation have been generally used since at least the early 1960's.
In the known prior art latch mechanisms, a latch pawl having an elongate body is secured to the lower housing. One end of the pawl engages a sized opening in the upper housing to latch and hold the housing together. A torsion spring affixed to side mounting pivot rods of the pawl acts to bias the pawl to its latched condition. A free end of the pawl extends through an opening in the lower housing and is accessible from the exterior of the luminaire. By manually pivoting the pawl against the bias of the torsion spring, the latching of the pawl to the latch opening in the upper housing is released and the lower housing is free to pivot about its hinged end to an open position allowing access to the upper housing cavity.
In the known and generally used latch mechanism, the pivot rod of the pawl is secured to the housing by suitable mounting screws. To assemble the mechanism, the unitary torsion spring is fitted on both ends of the pivot rod, the spring is squeezed or depressed and the latch pawl must be held in place while the mounting screws are assembled and tightened. For most applications, a mounting fixture is used to depress or squeeze the spring and hold the pawl in place until the screws can be tightened. With the luminaire mounted in an elevated position on a pole, the difficulty of using such fixtures and screw fastenings is readily apparent.
Further, it is well known that self-threading screws have a tendency toward premature embrittlement and resulting breakage. Breakage of a screw frequently requires replacement of the entire luminaire, since self-threading screws can rarely be removed, especially when the breakage is flush with the exposed surface of the screw receiver.
In many of the known devices, the latch strike opening was formed by mounting a latch strike member in the upper housing. The strike member is generally mounted at its lateral ends by screws into suitable bosses in the upper housing.